From mboxrd@z Thu Jan 1 00:00:00 1970 From: Wolfram Sang Subject: Re: [PATCH] i2c: xiic: Support disabling multi-master in DT Date: Thu, 2 Apr 2020 11:28:13 +0200 Message-ID: <20200402092813.GA986@ninjato> References: <20200218135627.24739-1-ext-jaakko.laine@vaisala.com> <20200401143254.GA2409@ninjato> Mime-Version: 1.0 Content-Type: multipart/mixed; boundary="===============1059516260593539739==" Return-path: In-Reply-To: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Sender: "linux-arm-kernel" Errors-To: linux-arm-kernel-bounces+linux-arm-kernel=m.gmane-mx.org@lists.infradead.org To: Laine Jaakko EXT , Rob Herring Cc: devicetree@vger.kernel.org, "michal.simek@xilinx.com" , Shubhrajyoti Datta , "linux-arm-kernel@lists.infradead.org" , "linux-i2c@vger.kernel.org" List-Id: linux-i2c@vger.kernel.org --===============1059516260593539739== Content-Type: multipart/signed; micalg=pgp-sha512; protocol="application/pgp-signature"; boundary="17pEHd4RhPHOinZp" Content-Disposition: inline --17pEHd4RhPHOinZp Content-Type: text/plain; charset=us-ascii Content-Disposition: inline Hi Jaako, > > My best bet is to introduce another binding "single-master" which says > > clearly that we are the only bus master on that bus. > > > > Both bindings missing means then "unclear". > > > > I think this matches reality best. > > > > Opinions? > I agree that this sounds like the best option if original binding > can't be used, even though it can also be a bit confusing to have 2 > similar bindings. I think it becomes understandable if we emphasize that "no bindings" means "unclear". We need to document it. > How would both bindings existing simultaneously be interpreted? Maybe > both existing simultaneously should be considered as an invalid > configuration, so that it would be enough to just check the one you > need? The other option would be to treat both existing similarly to > neither existing, which would require the driver to always check both > if checking one. I am clearly for saying that this is an illegal combination. I'd hope this can be expressed in a YAML binding. Yet, my research didn't give me an answer. Adding Rob and DT list to CC. Question is: Can we check if the boolean bindings "multi-master" and "single-master" are not applied at the same time? Any other combination is okay, i.e. just one of them or none of them. > Should the new single-master binding also be a general binding for all > I2C drivers or a binding just defined for the XIIC driver? Having it It should definately be global. Thanks, Wolfram --17pEHd4RhPHOinZp Content-Type: application/pgp-signature; name="signature.asc" -----BEGIN PGP SIGNATURE----- iQIzBAABCgAdFiEEOZGx6rniZ1Gk92RdFA3kzBSgKbYFAl6FsCkACgkQFA3kzBSg Kbbvtw/+L5wD8ARrOmtDVYzMRtJvbyu1XsD4cZdfx/fHNB3oOKbL65t9dnKWiuRy Np7KViYB9VbVGTYtRWPT5EPWUqhtNbRWfEoxONZ02IVVBq8qfl9iIgcXpvrbVU2J 7m3AJSB8x2A9FJ4iE1o3hPw7zkUKtnXui1nn7MIFO34d6QaU7UgxpQ3pIdITKtIm BqUedfcI2zj0cV+V4RsZFUlZLZ7QsVUkcXDd3tsXt/yKnBxPVV/pzqmsQzNrXI3Q evWAjIFHmBJzM4B3teelLwsE2toVGVtK/j4x5ZhTSkEpPBnkA++02xAVq+krdM+z AMBD8ZIoHwQzjoSNGcoEXprLkQmN2nbfl1dgvRGUPotJ8LDIYo5NyaRy4WYBh6xF QjnMQFg29QuuWCfXDKC8vNG1BN/DYUh+8Bzo7HCGiEPd7B/unsFqz7QxW6WCg29G MmHi+253Xq9LKDvC6OqB2+Dvc764BGI2xiVu4t4/iXXvWI0VkhCeoZkUdLkx19OR LKEw7ipKmhiX4sPvhtD38J6c4XKz1izB+4rzTq7ZZH+Vg1cNtYL3/riIfE9BwxjF A6KwJi6vXetZxROIxWTxj8BX9qjbhErOYDCTWPxFlj815S4RfDgqC5oiHIhGGr4m Vv3egui9LAtlne0QsqmR0PjP5hQ4fFp+78rjdoHgyyFAtKA9fnA= =KFqX -----END PGP SIGNATURE----- --17pEHd4RhPHOinZp-- --===============1059516260593539739== Content-Type: text/plain; charset="us-ascii" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit Content-Disposition: inline _______________________________________________ linux-arm-kernel mailing list linux-arm-kernel@lists.infradead.org http://lists.infradead.org/mailman/listinfo/linux-arm-kernel --===============1059516260593539739==--